A Study of Agitated Gas-Liquid Reactors with Concave Blade Impellers

Chen, Z. D.; Chen, J. J. J.

doi:10.1007/978-94-017-2290-2_4

Cited by 6 publications

(9 citation statements)

References 9 publications

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“…As expected, the gassed power input in both bioreactors decreased as gas flow rates increased. At flow numbers of Fl ≈ 0.04, the P G / P L ratio became constant, which has also been reported for traditional impellers, such as Rushton turbines and curved blade impellers . Surprisingly, the Mobius CellReady marine impeller showed a higher dependency on the flow rate ( P G / P L ∝ Fl −0.15 ) than the SmartGlass bioreactor impellers ( P G / P L ∝ Fl −0.04 ), which may be explained by the lower gas dispersion efficiency of the marine impeller.…”

Section: Resultssupporting

confidence: 60%

“…, temperature‐ and torque‐based measurement techniques prevail over others, something which is also confirmed by Table that summarizes some studies on power measurements described in the literature . Even though this overview is far from complete, it is obvious that the majority of these studies focused on standard stirrers, such as Rushton turbines , pitched blade impellers , curved blade impellers , or more modern stirrers, such as SCABA and Lightnin impellers. These are commonly used for agitation in baffled, flat‐bottomed tanks.…”

Section: Introductionmentioning

confidence: 77%

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Development of a method for reliable power input measurements in conventional and single‐use stirred bioreactors at laboratory scale

Kaiser

Werner

Jossen

et al. 2016

Engineering in Life Sciences

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Power input is an important engineering and scale‐up/down criterion in stirred bioreactors. However, reliably measuring power input in laboratory‐scale systems is still challenging. Even though torque measurements have proven to be suitable in pilot scale systems, sensor accuracy, resolution, and errors from relatively high levels of friction inside bearings can become limiting factors at smaller scales. An experimental setup for power input measurements was developed in this study by focusing on stainless steel and single‐use bioreactors in the single‐digit volume range. The friction losses inside the air bearings were effectively reduced to less than 0.5% of the measurement range of the torque meter. A comparison of dimensionless power numbers determined for a reference Rushton turbine stirrer (N P = 4.17 ± 0.14 for fully turbulent conditions) revealed good agreement with literature data. Hence, the power numbers of several reusable and single‐use bioreactors could be determined over a wide range of Reynolds numbers between 100 and >104. Power numbers of between 0.3 and 4.5 (for Re = 104) were determined for the different systems. The rigid plastic vessels showed similar power characteristics to their reusable counterparts. Thus, it was demonstrated that the torque‐based technique can be used to reliably measure power input in stirred reusable and single‐use bioreactors at the laboratory scale.

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Section: Resultssupporting

confidence: 60%

Section: Introductionmentioning

confidence: 77%

Development of a method for reliable power input measurements in conventional and single‐use stirred bioreactors at laboratory scale

Kaiser

Werner

Jossen

et al. 2016

Engineering in Life Sciences

View full text Add to dashboard Cite

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“…2 (see Figure 4 , Figure 5 , Figure 6 ). The standard Rushton turbine was used as a reference with well documented power numbers in the literature 1 16 17 18 19 20 21 22 23 24 25 . As can be seen from Figure 4a , the power number in the smaller 2 L vessel (bioreactor #1) decreased at low Reynolds numbers (100 < Re < ≈500) from P 0 = 6.3 to P 0 ≈ 3.3 before it increased again above Re ≈ 2000.…”

Section: Representative Resultsmentioning

confidence: 99%

“…stationary heat balance or dynamic heating through the agitation) or the torque upon the agitator. The latter can be experimentally determined by dynamometers, torque meters or strain gauges, which have been applied for a variety of agitators, including single or multi-stage Rushton turbines 1 16 17 18 19 20 21 22 23 24 25 , pitched blade impellers 19 20 23 26 27 , InterMig 19 21 and Scaba impellers 28 29 . A detailed review is provided by Ascanio et al (2004) 30 .…”

Section: Introductionmentioning

confidence: 99%

“…Nevertheless, power input measurements in small scale bioreactors are still challenging due to the relatively high friction losses inside mechanical bearings of the impeller shafts and the limited accuracy of most commercially available torque meters. Consequently, only a few reports about power input measurements in benchtop scale bioreactors have been published 17 18 22 24 31 32 . There is also a lack of data about the power input in single-use bioreactors, which are delivered by the manufacturers preassembled, sterilized and ready-to-use 33 34 .…”

Section: Introductionmentioning

confidence: 99%

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Power Input Measurements in Stirred Bioreactors at Laboratory Scale

Kaiser

Werner

Jossen

et al. 2018

JoVE

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The power input in stirred bioreactors is an important scaling-up parameter and can be measured through the torque that acts on the impeller shaft during rotation. However, the experimental determination of the power input in small-scale vessels is still challenging due to relatively high friction losses inside typically used bushings, bearings and/or shaft seals and the accuracy of commercially available torque meters. Thus, only limited data for small-scale bioreactors, in particular single-use systems, is available in the literature, making comparisons among different single-use systems and their conventional counterparts difficult.This manuscript provides a protocol on how to measure power inputs in benchtop scale bioreactors over a wide range of turbulence conditions, which can be described by the dimensionless Reynolds number (Re). The aforementioned friction losses are effectively reduced by the use of an air bearing. The procedure on how to set up, conduct and evaluate a torque-based power input measurement, with special focus on cell culture typical agitation conditions with low to moderate turbulence (100 < Re < 2·104), is described in detail. The power input of several multi-use and single-use bioreactors is provided by the dimensionless power number (also called Newton number, P0), which is determined to be in the range of P0 ≈ 0.3 and P0 ≈ 4.5 for the maximum Reynolds numbers in the different bioreactors.

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Automated End-to-End Workflow for Volumetric Mass-Transfer Coefficient (k_La) Characterization in Small-Molecule Pharmaceutical Development

Mattern,

Grosser

2023

Org. Process Res. Dev.

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Biocatalytic aerobic oxidations have recently emerged in the small-molecule pharmaceutical industry as a selective and green alternative to traditional chemocatalyzed oxidations that rely on transition-metal-based oxidants. Engineering aspects, such as mass transfer and reactor design, play a key role in determining the adoption and success of such biocatalytic aerobic oxidations; therefore, a detailed understanding and characterization of mass transfer at various process scales become a critical component of reaction development. Traditional mass-transfer characterization techniques are tedious to execute for a large number of processing conditions and reactor configurations and require careful experimental planning and data capture to ensure accurate regression of the volumetric mass-transfer coefficient, k L a. A custom-automated reactor characterization workflow has been developed to surmount these challenges and enable rapid design space characterization of mass transfer in reactors spanning the laboratory to production scales. Custom data compression and processing scripts paired with automated parameter regression enable rapid data processing and regression of experimental k L a values. Furthermore, a detailed analysis of system lag and error was conducted to enable more accurate modeling of system start-up during k L a experiments. This workflow has been leveraged to build a database of more than 2000 unique processing conditions in small-molecule centric, traditional batch chemistry reactors spanning laboratory development through manufacturing. This database allows scientists to quickly determine suitable processing conditions with a known k L a and mass-transfer performance, lowering the barriers to adoption and enabling rapid biocatalytic aerobic oxidation reaction development and scale-up.

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A Study of Agitated Gas-Liquid Reactors with Concave Blade Impellers

Cited by 6 publications

References 9 publications

Development of a method for reliable power input measurements in conventional and single‐use stirred bioreactors at laboratory scale

Development of a method for reliable power input measurements in conventional and single‐use stirred bioreactors at laboratory scale

Power Input Measurements in Stirred Bioreactors at Laboratory Scale

Automated End-to-End Workflow for Volumetric Mass-Transfer Coefficient (k_La) Characterization in Small-Molecule Pharmaceutical Development

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A Study of Agitated Gas-Liquid Reactors with Concave Blade Impellers

Cited by 6 publications

References 9 publications

Development of a method for reliable power input measurements in conventional and single‐use stirred bioreactors at laboratory scale

Development of a method for reliable power input measurements in conventional and single‐use stirred bioreactors at laboratory scale

Power Input Measurements in Stirred Bioreactors at Laboratory Scale

Automated End-to-End Workflow for Volumetric Mass-Transfer Coefficient (kLa) Characterization in Small-Molecule Pharmaceutical Development

Contact Info

Product

Resources

About

Automated End-to-End Workflow for Volumetric Mass-Transfer Coefficient (k_La) Characterization in Small-Molecule Pharmaceutical Development